Arsene Wenger was left to lament Arsenal's missed chances as they lost 2-0 to Bayern Munich in the Champions League.

The Gunners could have taken the lead in the ninth minute when Mesut Ozil was tripped in the box by Jerome Boateng.

Arsenal's German playmaker nonchalantly chipped the spot-kick into the hands of his childhood friend Manuel Neuer in the Bayern goal, before Yaya Sanogo and Alex Oxlade-Chamberlain both missed early chances.

After a hot start, Arsenal soon cooled and the defending champions eased their way into the game and should have taken the lead themselves just before the break when Wojciech Szczesny was sent off for a collision with Arjen Robben.

David Alaba missed the subsequent penalty but Bayern came to fore in the second period as Toni Kroos and Thomas Muller both fired beyond substitute goalkeeper Lukasz Fabianksi.

"We should have been three up before they got a sniff in the game and we made big mistakes, but the spirit was fantastic.

"The penalty we missed killed it a little bit, the crowd and the positive vibes."

Dispute

Wenger did criticise Ozil's penalty attempt, but questioned referee Nicola Rizzoli's decision to dismiss Szczesny after he offered Bayern an opportunity of their own to convert from 12 yards.

"I prefer people that properly hit the ball," he admitted. "Everybody has their own style and you have to respect that, there is no one way of penalty taking.

"There is contact, it is a penalty, is it a red card? I have disputed that many times."

Bayern enjoyed 79 per cent possession on the night, which meant Arsenal had a lot of chasing to do, but Wenger praised the energy of his side.

"When you have one player sent off and one injured (Kieran Gibbs), you know you are going to suffer physically," he said.

"It's a very difficult night but a night where the team has shown some quality and some class but at the end of the day, we lose the game."

Satisfaction

Sanogo - making his Champions League debut and only a second Arsenal start - was a surprise inclusion from Wenger, who left Olivier Giroud on the bench, but the Frenchman defended his team selection.

"I think he did very well," he claimed. "The overall feeling is one of satisfaction tonight.

"He worked very hard and showed commitment and quality.

"I think we had more problems when we were down to 10 men, Robben has caused problems for many players and teams."

Arsenal found themselves two goals down after their first leg against Bayern at the same stage last year and Wenger insists the Gunners will be prepared when they head to the Allianz Arena on March 11.

"We will go there and have a go in the second leg," he said.

"You never know, we won 2-0 in the second leg last year and we have to do the same again.